A lot of play were the yoke enters the t-case may be caused by the yoke and have nothing to do with the t-case. A sloppy yoke can also cause vibration and strange noises. I'd check that first before jumping into a t-case rebuild.

Edward

'97 Montero Sport LS 5-Speed 3.5L conversion
SAS Dana 44s & ARBs, 35" Yoko Geolandar M/Ts
NP231 B4R doubler/Terra Low231/RP 5.38 229:1
'99 Montero Sport Limited 4WD SAS 3-link project
'03 Montero Sport Limited AWD
'97 Montero Sport LS 5-Speed 4WD